Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) is a surface characterization technique which is based upon the liberation and identification of ions that are sputtered from a sample’s surface. This method is extremely surface sensitive since most of the liberated material comes from the top-most surface layers, yet it also has the capability to selectively etch away material and perform in-depth analysis. The data provide molecular and elemental information about the sample.
With this technique, the sample surface is interrogated with a pulsed beam of high energy primary ions. As the primary ions impact the sample their energy is transferred to the surface region, and this energy is sufficient to both release and ionize local molecules and atoms. The newly-formed secondary ions are accelerated into a mass analyzer where they are separated according to their mass-to-charge ratios. The mass-to-charge ratio is used to identify the species present in the sample. Fragmentation patterns and isotope ratios aid in the identification of many species in complex matrices.
For more information about this instrument, visit their website: Physical Electronics